National Geographic : 1977 Jul
On the watch for plague, technicians at the Haffkine Institute in Bombay (left) examine the previous day's city-wide kill of 3,500 to 4,500 rats, sorted into piles from different neighborhoods. Three Xenopsylla fleas, a genus known to harbor the Black Death bacillus, are magnified (above) at the Vertebrate Pest Con trol Centre in Karachi, Pakistan. History's most calamitous plague, the Black Death of the Middle Ages, killed an estimated 25 million people. Though plague had struck before--and still occurs today (map, below) not until 1908 was its carrier conclusively iden tified: fleas residing on rats and other rodents. Scholars speculate that plague was the dis ease recorded in the First Book of Samuel, but the presence of rats on the victims in a 13th century illustrated Bible (right) is viewed as the artist's literal rendition of "mice that mar the land" (I Samuel 6:5). PIERPONTMORGANLIBRARY * 20 C' " o SUNI STATES ERICA *PLAGUE Rats and other small mammals carry fleas A' bearing the plague AUSTRALIA COMPILEDBYPAMELANUET U bacterium Yersinia NATIONALGEOGRAPHICART DIVISION pestis to four continents. Known plague areas are shown in solid red; outlinedareas are suspected to hold plague-carrying rodents. Numbers represent reported human cases in 1975.